The disclosure relates to a method for manufacturing an optical element, where a blank of glass is heated and/or provided and, after heating and/or after being provided between a first mold (UF) and at least one second mold (OF), is press molded, for example on both sides, to form the optical element and is then sprayed with a surface treatment agent.
|
13. A method for producing a headlight lens, the method comprising:
providing a first mold;
providing at least one second mold;
providing a cooling path;
heating a blank made of soda-lime glass;
press-molding the heated blank to form the headlight lens having at least one first optically effective surface using the first mold and the at least one second mold;
spraying the at least one first optically effective surface with a surface-treatment agent which promotes cross linking of oxygen ions with silicon ions on the at least one first optically effective surface, wherein the surface-treatment agent comprises a solvent and a solid dissolved in the solvent, wherein the solid comprises an amount of ammonium sulfate; and
then, cooling the headlight lens in accordance with a cooling regime in the cooling path with the addition of heat to prevent any internal stress within the headlight lens.
1. A method for producing a headlight lens, the method comprising:
providing a first mold;
providing at least one second mold;
providing a cooling path;
providing a chamber;
providing a surface-treatment agent which comprises a solvent and a solid dissolved in the solvent, wherein the solid comprises an amount of ammonium sulfate;
providing a gas;
heating a blank made of soda-lime glass;
press-molding the heated blank to form the headlight lens having at least one first optically effective surface using the first mold and the at least one second mold; placing the headlight lens in the chamber;
generating a spray by thoroughly mixing the surface-treatment agent with the gas;
in the chamber, exposing the at least one first optically effective surface to the spray which promotes crosslinking of oxygen ions with silicon ions on the at least one first optically effective surface; and
then, cooling the headlight lens in accordance with a cooling regime in the cooling path with the addition of heat to prevent any internal stress within the headlight lens.
2. The method according to
3. The method according to
4. The method according to
5. The method according to
6. The method according to
7. The method according to
8. The method according to
9. The method according to
wherein Q(3) denotes 3 oxygen ions crosslinking at tetrahedron corners of a silicon ion and Q(4) denotes 4 oxygen ions crosslinking at tetrahedron corners of a silicon ion.
10. The method according to
11. The method according to
12. The method according to
14. The method according to
15. The method according to
16. The method according to
wherein Q(3) denotes 3 oxygen ions crosslinking at tetrahedron corners of a silicon ion and Q(4) denotes 4 oxygen ions crosslinking at tetrahedron corners of a silicon ion.
17. The method according to
wherein Q(3) denotes 3 oxygen ions crosslinking at tetrahedron corners of a silicon ion and Q(4) denotes 4 oxygen ions crosslinking at tetrahedron corners of a silicon ion.
18. The method according to
19. The method according to
20. The method according to
21. The method according to
22. The method according to
23. The method according to
wherein Q(3) denotes 3 oxygen ions crosslinking at tetrahedron corners of a silicon ion and Q(4) denotes 4 oxygen ions crosslinking at tetrahedron corners of a silicon ion.
24. The method according to
25. The method according to
|
The application claims the priority of the German patent application DE 10 2021 105 560.1, filed on 8. Mar. 2021, which is expressly incorporated by reference in its entirety.
The disclosure relates to a method for manufacturing an optical element, wherein a blank of transparent material is heated and/or provided and after being heated and/or after being provided between a first mold and at least one second mold is press molded, for example on both sides, to form the optical element.
Such a method discloses for example the WO 2019/072325 A1 and the WO 2019/072326 A1.
In addition to demands for particularly precise optical properties, the desire to press headlight lenses from borosilicate glass or glass systems similar to borosilicate glass has manifested itself in order to achieve increased weather resistance or hydrolytic resistance (chemical resistance). Standards or assessment methods regarding hydrolytic resistance (chemical resistance) are, for example, Hella standard test N67057 and climatic test/humidity-frost test. High hydrolytic resistance, for example, is also classified as type 1. In the light of the requirement for borosilicate-glass headlight lenses having corresponding hydrolytic resistance, the task arises of pressing headlight lenses from borosilicate glass or similar glass systems with the same hydrolytic resistance (chemical resistance). In a departure from this task, an alternative method for manufacturing an optical element or headlight lens from non-borosilicate glass and/or soda-lime glass is proposed. In order to ensure precise optical properties, a special contour accuracy with simultaneous surface quality, i.e. low roughness Ra, is desirable.
U.S. Pat. No. 7,798,688 B2 discloses a projection headlight comprising a headlight lens and a light source, wherein a surface intended to face away from the light source of the projection headlight comprises a layer which has an aluminum concentration that is greater than an aluminum concentration inside the headlight lens.
DE 10 2006 034 431 A1 discloses a method for the surface-finishing of alkali-containing glass, wherein hot surfaces are brought into contact with aluminum-chloride compounds from the vapor phase.
Compared to the surface treatment described in DE 10 2006 034 431 A1 for bottles with aluminum chloride and its solution in methanol, the teaching of EP 2 043 962 B1 sets out the need for a more durable surface when producing flat glass in a more efficient manner. This need is met in EP 2 043 962 B1 in that, when producing soda-lime-silicate based glass, the glass strip formed from the melt is passed to an annealing lehr, wherein the main surface of the glass strip being applied with aluminium chloride before the annealing lehr at a temperature between 540° C. and 850° C. by applying a mixture of AlCl3 and at least one solvent to the surface of the glass strip, wherein the mixture comprises 5-10% aluminum chloride and the solvent comprises ethanol.
The disclosure relates to a method for manufacturing an optical element or headlight lens. It is provided, for example, that a blank of non-borosilicate glass and/or of soda-lime glass (soda-lime silicate glass) is heated and/or provided and, after being heated and/or being provided between a first mold, for example for molding and/or for press-molding a first optically effective surface of the optical element, and at least one second mold, for example for molding and/or for press-molding a second optically effective surface of the optical element, is press-molded, for example on both sides, to form the optical element. It can be provided that the first optically effective surface and/or the second optically effective surface (after the press-molding) is sprayed (for example in a treatment chamber) with a surface treatment agent.
The disclosure relates to a method for manufacturing an optical element or a headlight lens. It is provided, for example, that a blank of non-borosilicate glass and/or of soda-lime glass (soda-lime silicate glass) is heated and/or provided and after heating and/or after being provided between a first mold, for example for molding and/or for press molding a first optically effective surface of the optical element, and at least one second mold, for example for molding and/or for press molding a second optically effective surface of the optical element, is press molded, for example on both sides, to form the optical element. It may be provided that the first optically effective surface and/or the second optically effective surface (after the press molding) is sprayed (for example in a treatment chamber) with a surface treatment agent, wherein the surface treatment agent comprises a solvent and a sulfate, for example ammonium sulfate, dissolved in the solvent. It may be provided that the solvent with the sulfate or ammonium sulfate dissolved therein is mixed with a gas and/or atomized by means of the gas.
A solvent in the sense of the present disclosure comprises, for example, water or is essentially water, but may optionally also be a solvent mixture. A solvent is substantially water or consists substantially of water if the water content is at least 90%, for example at least 95%. A gas in the sense of the present disclosure can also optionally be a gas mixture, for example compressed air.
For example, a surface is optically effective within the meaning of the present disclosure if it alters the direction of light passing through the surface during intended use with respect to its direction and/or its beam or bundle characteristics. For example, a surface is optically effective within the meaning of the present disclosure if, due to re-fraction, it alters the direction of light passing through the surface during intended use with respect to its direction and/or its beam or bundle characteristics.
surface, such as an edge, through which light is not intended to pass is for example not optically effective within the meaning of the present disclosure.
For the purposes of this disclosure, after the press molding is intended to mean, for example, that a subsequent or following step or process step takes place substantially immediately after the press molding, but at least without significant cooling of the press molded optical element. For the purposes of this disclosure, without significant cooling is intended to mean, for example, that cooling of less than 20%, for example less than 10%, in terms of degrees Celsius, takes place.
It is envisaged, for example, that the surface treatment agent has a temperature of not less than 15° C. during atomization. For example, it is provided that the surface treatment agent has a temperature of not more than 100° C., for example of not more than 50° C., for example of not more than 30° C., during atomization.
By contrast with the treatment of hollow glass or flat glass disclosed in EP 1 984 642 B1 and DE 10 2016 102 408 A1 the present disclosure relates to the treatment of optically effective surfaces. In this case, particularly high requirements are placed on the cooling, since not only mechanical damage, such as cracks, could result in the object becoming unusable, but also internal strain, due to excessively rapid cooling. Therefore, it is all the more surprising that hot optically effective surfaces can be successfully treated in a suitable manner by nebulizing or fogging or by using a spray, in order to increase its hydrolytic resistance.
For example, it is envisaged that the surface treatment is not followed by a mechanical polishing step, even after the optical element or headlight lens has cooled in a cooling path. It is for example intended that the improvement of the roughness Ra compared to an untreated lens to an untreated optical element is achieved solely by the surface treatment with sulfate or ammonium sulfate.
Within the meaning of this disclosure, soda-lime glass for example comprises
Within the meaning of this disclosure, soda-lime glass for example comprises
Within the meaning of this disclosure, soda-lime glass for example comprises
Within the meaning of this disclosure, soda-lime glass for example comprises
Within the meaning of this disclosure, soda-lime glass for example comprises
Within the meaning of this disclosure, soda-lime glass for example comprises
In one embodiment, the solvent comprises, in addition to water, suspending agents, alcohol, methanol, ethanol, carbon-based solvents, and/or isopropanol. In one embodiment, it is provided that the solvent is substantially water or comprises water or that the solvent has water as an essential component.
For example, it is provided that the amount of sulfate or ammonium sulfate in solvent is at least 10% by weight, for example at least 20% by weight. For example, it is provided that the amount of sulfate or ammonium sulfate in solvent is not more than 50 wt %, for example not more than 40 wt %.
In one embodiment, it is provided that the gas comprises or consists of one or more of air, nitrogen, hydrogen, carbon dioxide, and/or SO2. However, in one embodiment, it is provided that the gas comprises essentially air or compressed air or consists of compressed air.
Ammonium nitrate may be used instead of ammonium sulfate, or may be used supplementally together with ammonium sulfate. However, ammonium sulfate may be used.
In one embodiment, it is provided that the first optically effective surface is exposed to a different surface treatment agent than the second optically effective surface. It is provided, for example, that the surface treatment agent differs in the proportion of sulfate or ammonium sulfate in the solvent and/or with respect to the pressure of the compressed air.
It may be provided that at least one optically effective surface is fire-polished before the treatment with surface-treatment agent. In one configuration, it is for example provided that only the underside is fire-polished. This is, for example, provided in connection with a configuration of the lower optically effective surface as a planar surface. It has been found to be suitable, when fire polishing is provided, a waiting time to be allowed to elapse before the surface is exposed to the surface-treatment agent. The waiting time is for example at least two seconds, for example at least three seconds, for example at least four seconds. In one configuration, the fire polishing lasts no longer than three seconds, for example no longer than two seconds.
For large lenses, waiting times or hold times may for example be at least 20 seconds but, for example, no more than 50 seconds.
In one embodiment, the first optically effective surface and the second optically effective surface are sprayed with the surface-treatment agent at least partially simultaneously (overlapping in time).
In an embodiment the temperature of the optical element and/or the temperature of the first optically effective surface and/or the temperature of the second optically effective surface during spraying with surface-treatment agent is no less than TG or TG+20° K, wherein TG denotes the glass transition temperature. In another embodiment, the temperature is no less than TG-50° K.
In an embodiment the temperature of the optical element and/or the temperature of the first optically effective surface and/or the temperature of the second optically effective surface during spraying with surface-treatment agent is no greater than TG+150° K, for example no greater than TG+100° K.
In an embodiment the surface-treatment agent in the form of a spray agent is sprayed onto the optically effective surface, wherein the surface-treatment agent forms droplets, of which the size and/or the average size and/or the diameter and/or the average diameter is no greater than 50 μm.
In an embodiment the surface-treatment agent in the form of a spray agent is sprayed onto the optically effective surface, wherein the surface-treatment agent forms droplets, of which the size and/or the average size and/or the diameter and/or the average diameter is no less than 10 μm.
In an embodiment the surface-treatment agent is sprayed so as to be mixed with compressed air. In an embodiment compressed air, for example in combination with a mixing nozzle or dual-substance nozzle, is used for generating a spray for the surface-treatment agent. In an embodiment the surface-treatment agent is sprayed so as to be mixed with gas. In an embodiment a gas or gas mixture (for example in combination with a pressure of at least two bar), for example in combination with a mixing nozzle or dual-substance nozzle, is used for generating a spray for the surface-treatment agent. The gas is mixed with the surface-treatment agent under pressure (e.g. at least two bar or at least three bar), for example. The gas is, for example, mixed with the gas (immediately) before impinging on the optically effective surface. In one configuration, the gas may be or contain nitrogen and/or carbon dioxide.
In an embodiment the optically effective surface is sprayed with the surface-treatment agent before the optical element is cooled in a cooling path for cooling in accordance with a cooling regime.
It is for example provided that residues are removed, for example washed away, from the surface-treatment process. This may for example be carried out using water, without the addition of cleaning agents. After being treated with the surface-treatment agent, the optical elements may have a (white) deposit, for example the reaction product. VE water may for example be used for cleaning the optical elements. VE water is demineralized water. The abbreviation VE stands for “vollentsalzt (deionized)”. The cleaning may for example be carried out at a water
temperature of 60° C. of the VE water. It is not necessary to use a washing agent such as CEROWEG, which is known from WO 2019/243 343 A1.
It is for example provided that the optical element or lens has a transmission of greater than 90% after washing and/or removing residues from the surface-treatment process.
In another exemplary configuration, an optically effective surface is sprayed with the surface-treatment agent for no longer than 4 seconds. In other exemplary configurations, the optically effective surface is sprayed with the surface-treatment agent for example for no longer than 3 seconds, for example for no longer than 2 seconds, for example for no longer than one second. In this process for example, the optically effective surface is sprayed until it has been sprayed with no less than 0.05 ml surface-treatment agent and/or with no more than 0.5 ml, for example 0.2 ml, surface-treatment agent.
It is for example provided that the optically effective surface of the headlight lens according to the present disclosure after being sprayed with surface-treatment agent consists of at least 90%, for example at least 95%, for example (substantially) 100%, quartz glass on the surface, produced by crosslinking of oxygen ions with silicon ions on the optically effective surface. It is for example provided that the amount of cross-linking of oxygen ions to silicon ions on the optically effective surface of the headlight lens or the optical element after the spraying can be represented by the relationship:
and in further example, can be represented by the relationship:
In the above, Q(3) denotes 3 oxygen ions crosslinking at tetrahedron corners of a silicon ion and Q(4) denotes 4 oxygen ions crosslinking at tetrahedron corners of a silicon ion. The proportion of quartz glass decreases from the optically effective surface towards the interior of the headlight lens or optical element, wherein, at a depth (distance from the surface) of 5 μm, it is for example provided that the proportion of quartz glass is at least 10%, for example at least 5%. It is for example provided that the amount of the crosslinking of oxygen ions to silicon ions at a depth of 5 μm below the optically effective surface of the headlight lens or the optical element after the spraying can be represented by the relationship:
and in further example, can be represented by the relationship:
It is for example provided that the proportion of quartz glass at a depth (distance from the surface) of 5 μm is no greater than 50%, for example no greater than 25%. It is for example provided that the amount of the crosslinking of oxygen ions to silicon ions at a depth of 5 μm below the optically effective surface of the headlight lens or the optical element after the spraying can be represented by the relationship:
and in further example, can be represented by the relationship:
No crosslinking of oxygen ions and silicon ions is observed before the surface treatment by spraying with the described surface-treatment agent. For example, no ion cross-linking takes place in the sense of the first phase as disclosed in DE 697 01 714 T2. Instead, for example, only a dealkalization takes place, using the term similar to that used in DE 697 01 714 T2, but without adopting the parameters used there.
In an embodiment the first mold is moved by means of an actuator for moving the first mold by the first mold and the actuator being connected by means of a first movable guide rod and at least one second movable guide rod, for example at least one third movable guide rod, wherein the first movable guide rod is guided in a recess in a fixed guide element and the second movable guide rod is guided in a recess in the fixed guide element and the optional third movable guide rod is guided in a recess in the fixed guide element, wherein it is for example provided that the deviation in the position of the mold orthogonally to the movement direction of the mold from the target position of the mold orthogonally to the movement direction of the mold is no greater than 20 μm, for example no greater than 15 μm, for example no greater than 10 μm.
In another embodiment the at least one second mold is moved by means of an actuator for moving the second mold in a frame, which comprises a first fixed guide rod, at least one second fixed guide rod and for example at least one third guide rod, wherein the first fixed guide rod, the at least one second fixed guide rod and the optional at least one third guide rod are connected at one end by an actuator-side fixed connector and at the other end by a mold-side fixed connector, wherein the at least one second mold is fixed to a movable guide element, which comprises a recess through which the first fixed guide rod is guided, another recess through which the at least one second fixed guide rod is guided, and optionally another recess through which the optional third fixed guide rod is guided, wherein it is for example provided that the deviation in the position of the mold orthogonally to the movement direction of the mold from the target position of the mold orthogonally to the movement direction of the mold is no greater than 20 μm, for example no greater than 15 μm, for example no greater than 10 μm.
In an embodiment it is for example provided that the first mold is moved by means of an actuator for moving the first mold by the first mold and the actuator for moving the first mold being connected by means of a first movable guide rod
and at least one second movable guide rod, for example at least one third movable guide rod, wherein the first movable guide rod is guided in a recess in a fixed guide element and the second movable guide rod is guided in a recess in the fixed guide element and the optional third movable guide rod is guided in a recess in the fixed guide element.
In an embodiment it is provided that the fixed guide element is identical to the mold-side fixed connector or is indirectly or directly fixed thereto.
In an embodiment the first mold is a lower mold and/or the second mold is an upper mold.
In an embodiment it is provided that, before pressing, the blank is placed onto an annular or free-form support surface of a carrier body having a hollow cross section, and is heated on the carrier body, for example such that a temperature gradient is produced in the blank such that the blank is cooler in its interior than on its outer region. It is for example provided that the support surface is cooled by means of a coolant flowing through the carrier body, wherein it is for example provided that the support surface spans a base surface that is not circular. In this case, a geometry of the support surface or a geometry of the base surface of the support surface is for example provided which corresponds to the geometry of the blank (to be heated), wherein the geometry is selected such that the blank rests on the outer region of its underside (underside base surface). The diameter of the underside or the underside base surface of the blank is at least 1 mm greater than the diameter of the base surface spanned (by the carrier body or its support surface). In this sense, it is for example provided that the geometry of the surface of the blank facing the carrier body corresponds to the support surface or the base surface. This for example means that, after the forming process or the pressing or press molding, the part of the blank resting on the carrier body or contacting the carrier body during heating is arranged in an edge region of the headlight lens which lies outside the optical path and rests on a transport element (see below) or its (corresponding) support surface, for example.
An annular support surface may comprise small discontinuities. Within the meaning of this disclosure, a base surface is for example an imaginary surface (in the region of which the blank resting on the carrier body is not in contact with the carrier body), which lies in the plane of the support surface and is surrounded by this support surface, plus the support surface. It is for example provided that the blank and the carrier body are coordinated with one another. This is for example understood to mean that the edge region of the blank rests on the carrier body on its underside. An edge region of a blank can be understood to mean the outer 10% or the outer 5% of the blank or its underside, for example.
Within the meaning of this disclosure, a blank is for example a portioned glass part or a preform or a gob.
Within the meaning of this disclosure, an optical element is for example a lens, for example a headlight lens or a lens-like free-form. Within the meaning of this disclosure, an optical element is for example a lens or a lens-like free-form comprising a supporting edge that is circumferential, discontinuous or circumferential in a discontinuous manner. Within the meaning of this disclosure, an optical element may e.g. be an optical element as described in
The claimed method is used, for example, for headlight lenses without surface structures or without deliberately imprinted or shaped or provided surface structures or without (deliberately) soft-drawing surface structures. The claimed method is used, for example, for headlight lenses without deterministic surface structures, such as disclosed in WO 2015/031925 A1, and, for example, without deterministic non-periodic surface structures, such as disclosed in DE 10 2011 114 636 A1. The claimed method or the disclosed method may also be used for optical elements or headlight lenses with surface structures.
In an embodiment the base surface is polygon-shaped or polygonal, but for example with rounded corners, wherein it is for example provided that the underside base surface of the blank is also polygon-shaped or polygonal, but for example with rounded corners. In another exemplary configuration, the base surface is triangle-shaped or triangular, but for example with rounded corners, wherein it is for example provided that the underside base surface of the blank is also triangle-shaped or triangular, but for example with rounded corners. In one configuration, the base surface is rectangle-shaped or rectangular, but for example with rounded corners, wherein it is for example provided that the underside base surface of the blank is also rectangle-shaped or rectangular, but for example with rounded corners. In another exemplary configuration, the base surface is square, but for example with rounded corners, wherein it is for example provided that the underside base surface of the blank is also square, but for example with rounded
corners. In another exemplary configuration, the base surface is oval, wherein it is for example provided that the underside base surface of the blank is also oval.
In an embodiment, the carrier body is tubular at least in the region of the support surface. The carrier body for example consists (at least substantially) of steel or high-alloy steel (i.e. for example a steel in which the average mass content of at least one alloy element is ≥5%) or of a tube made of steel or high-alloy steel. In another embodiment the diameter of the hollow cross section of the carrier body or the internal tube diameter, at least in the region of the support surface, is no less than 0.5 mm and/or no greater than 1 mm. In an embodiment the external diameter of the carrier body or the external tube diameter, at least in the region of the support surface, is no less than 2 mm and/or no greater than 4 mm, for example no greater than 3 mm. In an embodiment the radius of curvature of the support surface orthogonally to the flow direction of the coolant is no less than 1 mm and/or no greater than 2 mm, for example no greater than 1.5 mm. In another exemplary configuration, the ratio of the diameter of the hollow cross section of the carrier body, at least in the region of the support surface, to the external diameter of the carrier body, at least in the region of the support surface, is no less than ¼ and/or no greater than ½. In an embodiment the carrier body is uncoated at least in the region of the support surface. In an embodiment coolant flows through the carrier body in accordance with the counterflow principle. In an embodiment the coolant is additionally and/or actively heated. In an embodiment the carrier body comprises at least two flow channels for the coolant flowing therethrough, which each only extend over a section of the annular support surface, wherein it is for example provided that two flow channels are connected in a region in which they leave the support surface by means of metal filler material, for example solder.
In an embodiment it is provided that, after press molding, the optical element is placed on a transport element, is sprayed with surface-treatment agent on the transport element and, thereafter or subsequently, passes through an cooling path on the transport element without an optical surface of the optical element being touched. Within the meaning of this disclosure, a cooling path is for example used for the controlled cooling of the optical element (for example with the addition of heat). Exemplary cooling regimes may e.g. be found in “Werkstoffkunde Glas” [Glass Materials Science], 1st edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig VLN 152-915/55/75, LSV 3014, editorial deadline: 1.9.1974, order number: 54107, e.g. page 130 and “Glastechnik-BG 1/1-Werkstoff Glas” [Glass Technology-vol. 1/1-Glass: The Material], VEB Deutscher Verlag für Grundstoffindustrie, Leipzig 1972, e.g. page 61 ff (incorporated by reference in its entirety). It is necessary to comply with a cooling regime of this kind in order to prevent any internal stresses within the optical element or the headlight lens, which, although they are not visible upon visual inspection, can sometimes significantly impair the lighting properties as an optical element of a headlight lens. These impairments result in a corresponding optical element or headlight lens becoming unusable. It has surprisingly been found that, although spraying the hot optical element or headlight lens after press molding or after removal from the mold following the press molding changes the cooling regime, the resulting optical stresses are negligible. It is also surprising that a corresponding headlight lens ranges between the above-mentioned optical tolerances in relation to its optical property, although the refractive index is reduced by the proportion of quartz glass on the surface.
In an embodiment the transport element consists of steel. For clarification: The transport element is not part of the lens (or headlight lens), and the lens (or headlight lens) and the transport element are not part of a common, integral body.
In an embodiment the transport element is heated, for example inductively, before receiving the optical element. In an embodiment the transport element is heated at a heating rate of at least 20 K/s, for example of at least 30 K/s. In an embodiment the transport element is heated at a heating rate of no greater than 50 K/s. In an embodiment the transport element is heated by means of an energized winding/coil winding which is arranged above the transport element.
In an embodiment the optical element comprises a support surface, which lies outside the light path provided for the optical element, wherein the support surface, for example only the support surface, is in contact with a corresponding support surface of the transport element when the optical element is placed on the transport element. In an embodiment the support surface of the optical element is on the edge of the optical element. In an embodiment the transport element comprises at least one limiting surface for orienting the optical element on the transport element and for limiting or preventing a movement of the optical element on the transport element. In an embodiment the limiting surface or surfaces are provided above the corresponding support surface of the transport element. In an embodiment (at least) two limiting surfaces are provided, wherein it may be provided that one limiting surface is below the corresponding support surface of the transport element and one limiting surface is above the corresponding support surface of the transport element. In an embodiment the transport element is adapted, i.e. manufactured, for example milled, to the optical element or the support surface of the optical element.
The transport element or the support surface of the transport element is annular, for example, but is not circular, for example.
In another embodiment the preform is produced, cast and/or molded from molten glass. In an embodiment the mass of the preform is 20 g to 400 g.
In an embodiment the temperature gradient of the preform is set such that the temperature of the core of the preform is above 10° K+TG.
In an embodiment to reverse its temperature gradient, the preform is first cooled, for example with the addition of heat, and then heated, wherein it is for example provided that the preform is heated such that the temperature of the surface of the preform after heating is at least 100° K, for example at least 150° K, higher than the glass transition temperature TG. The glass transition temperature TG is the temperature at which the glass becomes hard. Within the meaning of this disclosure, the glass transition temperature TG is for example intended to be the temperature of the glass at which it has a viscosity log in a range around 13.2 (corresponding to 1013.2 Pas), for example between 13 (corresponding to 1013 Pas) and 14.5 (corresponding to 1014.5 Pas). In relation to the glass type B270, the transition temperature TG is approximately 530° C.
In an embodiment the temperature gradient of the preform is set such that the temperature of the upper surface of the preform is at least 30° K, for example at least 50° K, above the temperature of the lower surface of the preform. In an embodiment the temperature gradient of the preform is set such that the temperature of the core of the preform is at least 50° K below the temperature of the surface of the preform. In an embodiment the preform is cooled such that the temperature of the preform before the heating is TG-80° K to TG+30° K. In an embodiment the temperature gradient of the preform is set such that the temperature of the core of the preform is 450° C. to 550° C. The temperature gradient is for example set such that the temperature in the core of the preform is below TG or close to TG. In an embodiment the temperature gradient of the preform is set such that the temperature of the surface of the preform is 700° C. to 900° C., for example 750° C. to 850° C. In an embodiment the preform is heated such that its surface assumes a temperature (for example immediately before pressing) that corresponds to the temperature at which the glass of the preform has a viscosity log between 5 (corresponding to 105 Pas) and 8 (corresponding to 108 Pas), for example a viscosity log between 5.5 (corresponding to 105.5 Pas) and 7 (corresponding to 107 Pas).
It is for example provided that, before reversing the temperature gradient, the preform is removed from a mold for molding or producing the preform. It is for example provided that the temperature gradient is reversed outside a mold. Within the meaning of this disclosure, cooling with the addition of heat for example means that cooling is carried out a temperature of greater than 100° C.
Within the meaning of this disclosure, press molding is for example understood to mean pressing a (for example optically effective) surface such that subsequent finishing of the contour of this (for example optically effective) surface is or can be omitted or is not provided. It is thus for example provided that a press molded surface is not polished after the press molding. Polishing, which influences the surface finish but not the contours of the surface, may be provided in some cases. Press molding on both sides can for example be understood to mean that
a (for example optically effective) light exit surface is press molded and a (for example optically effective) light entry surface that is for example opposite the (for example optically effective) light exit surface is likewise press molded.
In one configuration, the blank is placed onto an annular support surface of a carrier body having a hollow cross section, and is heated on the carrier body for example such that a temperature gradient is set in the blank such that the blank is cooler in its interior than on its outer region, wherein the support surface is cooled by means of a coolant flowing through the carrier body, wherein the blank made of glass, after being heated, is press molded, for example on both sides, to form the optical element, wherein the carrier body comprises at least two flow channels for the coolant flowing therethrough, which each only extend over a section of the annular support surface, and wherein two flow channels are connected in a region in which they leave the support surface by means of metal filler material, for example solder.
Within the meaning of this disclosure, a guide rod may be a rod, a tube, a profile, or the like.
Within the meaning of this disclosure, “fixed” for example means directly or indirectly fixed to a base of the pressing station or the press or a base on which the pressing station or press stands. Within the meaning of this disclosure, two elements are then fixed to one another, for example, when it is not provided that they are moved relative to one another for pressing.
For pressing, the first and the second mold are for example moved towards one another such that they form a closed mold or cavity or a substantially closed mold or cavity. Within the meaning of this disclosure, “moved towards one another” for example means that both molds are moved. It may, however, also mean that only one of the two molds is moved.
Within the meaning of the disclosure, a recess for example includes a bearing that couples or connects the recess to the corresponding guide rod. Within the meaning of this disclosure, a recess may be widened to form a sleeve or may be designed as a sleeve. Within the meaning of this disclosure, a recess may be widened to form a sleeve comprising an inner bearing or may be designed as a sleeve comprising an inner bearing.
In a matrix headlight, the optical element or a corresponding headlight lens is for example used as a secondary lens for imaging front optics. Within the meaning of this disclosure, front optics are for example arranged between the secondary optics and a light-source assembly. Within the meaning of this disclosure, front optics are for example arranged in the light path between the secondary optics and the light-source assembly. Within the meaning of this disclosure, front optics are for example an optical component for forming a light distribution depending on the light that is generated by the light-source assembly and is directed therefrom into the front optics. Here, a light distribution is generated or formed for example by TIR, i.e. by total reflection.
The optical element or a corresponding lens according to the present disclosure is also used in a projection headlight, for example. In the configuration as a headlight lens for a projection headlight, the optical element or a corresponding lens forms the edge of a shield in the form of a bright-dark-boundary on the carriageway.
Within the meaning of this disclosure, a motor vehicle is for example a land vehicle that can be used individually in road traffic. Within the meaning of this disclosure, motor vehicles are not limited to land vehicles comprising internal combustion engines, for example.
The thickness r of the lens edge 206 according to
It may be provided that the illumination device F4 also comprises front optics F42 for generating a light pattern (such as L4) on the light exit surface F421 on the basis of the accordingly actuated regions or pixels of the light-source assembly F41 or according to the light L41 directed into the front optics F42.
Within the meaning of this disclosure, matrix headlights may also be matrix SSL HD headlights. Examples of headlights of this kind are found at the links www.spring-erprofessional.de/fahrzeug-lichttechnik/fahrzeugsicherheit/hella-bringt-neues-ssl-hd-matrix-lichtsystem-auf-den-markt/17182758 (retrieved on 28 May 2020), www.highlight-web.de/5874/hella-ssl-hd/(retrieved on 28 May 2020) and www.hella.com/techworld/de/Lounge/Unser-Digital-Light-SSL-HD-Lichtsystem-ein-neuer-Meilenstein-der-automobilen-Lichttechnik-55548/(retrieved on 28 May 2020).
Another suitable field of application for lenses produced according to the disclosure is for example disclosed in DE 10 2017 105 888 A1 or the headlight described with reference to
The light module M20 comprises a controller denoted by reference sign M3, which actuates the light-emission unit M4 depending on the values from a sensor system or surround sensor system M2. The concave lens M5 comprises a concave curved exit surface on the side facing away from the light-emission unit M4. The exit surface of the concave lens M5 deflects light ML4 directed into the concave lens M5 from the light-emission unit M4 at a large emission angle towards the edge of the concave lens by means of total reflection, such that said light is not transmitted through the projection optics M6. According to DE 10 2017 105 888 A1, light beams that are emitted from the light-emission unit M4 at a “large emission angle” are referred to as those light beams which (without arranging the concave lens M5 in the beam path) would be imaged poorly, for example in a blurred manner, on the carriageway by means of the projection optics M6 owing to optical aberrations and/or could result in scattered light, which reduces the contrast of the imaging on the carriageway (see also DE 10 2017 105 888 A1). It may be provided that the projection optics M6 can only image light in focus at an opening angle limited to approximately +/−20°. Light beams having opening angles of greater than +/−20°, for example greater than +/−30°, are therefore prevented from impinging on the projection optics M6 by arranging the concave lens M5 in the beam path.
The light-emission unit M4 may be designed differently. According to one configuration, the individual punctiform light sources of the light-emission unit M4 each comprise a semiconductor light source, for example a light-emitting diode (LED). The LEDs may be actuated individually or in groups in a targeted manner in order to activate or deactivate or dim the semiconductor light sources. The light module M20 e.g. comprises more than 1,000 individually actuatable LEDs. For example, the light module M20 may be designed as what is known as a μAFS (micro-structured adaptive front-lighting system) light module.
According to an alternative option, the light-emission unit M4 comprises a semiconductor light source and a DLP or micromirror array, which comprises a large number of micromirrors which can be actuated and tilted individually, wherein each of the micromirrors forms one of the punctiform light sources of the light-emission unit M4. The micromirror array for example comprises at least 1 million micromirrors, which may for example be tilted at a frequency of up to 5,000 Hz.
Another example of a headlight system or light module (DLP system) is disclosed by the link www.al-lighting.com/news/article/digital-light-millions-of-pixels-on-the-road/(retrieved on 13.4.2020).
A controller G4 is provided for actuating the system G6 comprising movable micromirrors. In addition, the headlight G20 comprises a controller G3 both for synchronizing with the controller G4 and for actuating the illumination device G5 depending on the surround sensor system G2. Details of the controllers G3 and G4 can be found at the link www.al-lighting.com/news/article/digital-light-millions-of-pixels-on-the-road/(retrieved on 13.4.2020). The illumination device G5 may for example comprise an LED assembly or a comparable light-source assembly, optics such as a field lens (which, for example, has likewise been produced according to the above-described method) and a reflector.
The vehicle headlight G20 described with reference to
Sensor systems for the above-mentioned headlights for example comprise a camera and analysis or pattern recognition for analyzing a signal provided by the camera. A camera for example comprises an objective or a multiple-lens objective as well as an image sensor for imaging an image generated by the objective on the image sensor. In a particularly suitable manner, an objective is used as disclosed in U.S. Pat. No. 8,212,689 B2 (incorporated by reference in its entirety) and shown by way of example in
Another embodiment for the use of the method described in the following is the production of microlens arrays, for example microlens arrays for projection displays. A microlens array of this kind and its use in a projection display are shown in
The device 1 according to
The process step 122 is followed by a process step 123, in which the preform is transferred to the cooling apparatus 5 by means of a transfer station 4 and is cooled by means of the cooling apparatus 5 at a temperature of between 300° C. and 500° C., for example of between 350° C. and 450° C. In the present embodiment, the preform is cooled for over 10 minutes at a temperature of 400° C., such that its temperature in the interior is approximately 500° C. or greater, for example 600° C. or greater, for example TG or greater.
In a subsequent process step 124, the preform is heated by means of the heating apparatus 6 at a temperature of no less than 700° C. and/or no greater than 1600° C., for example of between 1,000° C. and 1250° C., wherein it is for example provided that the preform is heated such that the temperature of the surface of the preform after the heating is at least 100° C., for example at least 150° C., greater than TG and is for example 750° C. to 900° C., for example 780° C. to 850° C. A combination of the cooling apparatus 5 with the heating apparatus 6 is an example of a temperature-control apparatus for setting the temperature gradient.
In one configuration, this temperature-control apparatus and/or the combination of the heating apparatuses 5 and 6 is designed as a hood-type annealing furnace 5000, as shown in
The protective covers 5002, 5202, 5302 for example have the purpose of protecting the heating coils 5001 positioned in the furnace against glass bursting open. If a gob bursts open in the furnace without this protective cover, a part of the glass or a large part of the glass clings to the heating coils 5001 and thus significantly impairs the heating process for the next gob or even destroys the heating coils 5001 and thus destroys the entire functional capability of the furnace. The protective covers 5002, 5202, 5302 are removed after a gob has burst and are replaced by other protective covers. The protective covers 5002, 5202, 5302 are adapted to the size of the furnace.
The heating coils 5001 can consist of or comprise a plurality of independently actuatable heating coils 5001A and 5001B. Because said coils are independently actuatable, a particularly suitable, for example homogeneous, temperature (distribution) can be obtained inside the furnace or inside the protective covers 5002, 5202, 5303. In addition to their function of reducing the severity of a gob bursting open, the protective covers 5002, 5202, 5303 contribute to this desired temperature distribution. The protective covers consist of or comprise silicon carbide, for example.
As explained below with reference to
In order to reverse its temperature gradient, in one configuration, a preform resting on a cooled lance (not shown) is moved through the temperature-control device comprising the cooling apparatus 5 and the heating apparatus 6 (for example substantially continuously) or is held in one of the cooling apparatuses 5 and/or one of the heating apparatuses 6. A cooled lance is disclosed in DE 101 00 515 A1 and in DE 101 16 139 A1. Depending on the shape of the preform,
For the term “lance”, the term “support device” is also used in the following. The support device 400 shown in
The support device 500 shown in
It may be provided that, after passing through the cooling apparatus 5 (in the form of a cooling path), preforms are removed and are supplied by means of a transport apparatus 41, for example, to an intermediate storage unit (e.g. in which they are stored at room temperature). In addition, it may be provided that preforms are con-ducted to the transfer station 4 by means of a transport apparatus 42 and are phased into the continuing process by heating in the heating apparatus 6 (for example starting from room temperature).
In a departure from the method described with reference to
In the subsequent process step 123′ according to
Flat gobs, wafers or wafer-like preforms can also be used to produce microlens arrays. Wafers of this kind may be square, polygonal or round, for example having a thickness of from 1 mm to 10 mm and/or a diameter of 4 inches to 5 inches. In a departure from the previously described method, these preforms are not heated on support devices, as shown in
A press 8, onto which a preform is transferred by means of a transfer station 7, is provided behind the heating apparatuses 6 or 5000. The preform is blank-pressed, for example on both sides, to form an optical element, such as the headlight lens 202, in a process step 125 by means of the press 8. A suitable mold set is disclosed e.g. in EP 2 104 651 B1.
The pressing unit PO comprises an actuator O10, which moves the mold OF and is connected to a movable guide element O12. The pressing unit PO also comprises a frame, which is formed by an actuator-side fixed connector O11 and a mold-side fixed connector O14 as well as fixed guide rods O51 and O52, which connect the actuator-side fixed connector O11 to the mold-side fixed connector O14. The fixed guide rods O51 and O52 are guided through recesses in the movable guide element O12, such that they prevent, reduce or avoid any movement or deflection of the mold OF orthogonally to the movement direction of the actuator O10 or mold OF.
In the embodiment shown, the pressing units PO and PU are linked in that the fixed guide element UO is identical to the mold-side fixed connector O14. By linking or chaining the two pressing units PO and PU of the pressing station PS together, particularly high quality (for example in the form of contour accuracy) of the headlight lenses to be pressed is achieved.
The pressing station 800 comprises a lower pressing unit 801 and an upper pressing unit 802 (see
The lower pressing unit 801 comprises a press drive 840 corresponding to the actuator U10, by means of which drive three rods 841, 842, 843 are movable, in order to move a lower press mold 822 that is coupled to the rods 841, 842, 843 and corresponds to the mold UF. The rods 841, 842, 843 are guided through bores or holes (not shown) in the plate 817 and a plate 821, which prevent or considerably reduce a deviation or movement of the press mold 822 in a direction orthogonal to the movement direction. The rods 841, 842, 843 are embodiments of the movable guide rods U51 and U52 according to
The upper pressing unit 802 shown in
Reference sign 870 denotes a movement mechanism by means of which an induction heater 879 comprising an induction loop 872 can be moved towards the lower mold 822 in order to heat it by means of the induction loop 872. After the heating by means of the induction loop 872, the induction heater 879 is moved back into its starting position again. A gob or preform is placed onto the press mold 822 and, by moving the press molds 822 and 823 towards one another, is-press molded (on both sides) to form a headlight lens.
The components are, for example, coordinated with one another and/or dimensioned such that the maximum tilting ΔKIPOF or the maximum angle of the tilting of the mold OF (corresponding to the angle between the target pressing direction ACHSOF* and the actual pressing direction ACHSOF), as shown in
The components are, for example, coordinated with one another and/or dimensioned such that the maximum tilting ΔKIPUF or the maximum angle of the tilting of the mold UF (corresponding to the angle between the target pressing direction ACHSUF* and the actual pressing direction ACHSUF), as shown in
Additionally or alternatively, it may be provided that the actuator O10 is decoupled with regard to torsion from the movable guide element O12 with the mold OF. In addition, it may be provided that the actuator U10 is also decoupled with regard to torsion from the mold-side movable connector U12 with the mold UF.
The method described may also be carried out in connection with pressing under vacuum or near vacuum or at least under negative pressure in a chamber, as disclosed by way of example in JP 2003-048728 A. The method described may also be carried out in connection with pressing under vacuum or near vacuum or at least under negative pressure by means of a bellows, as explained in the following on the basis of the pressing station PS in
In another exemplary configuration, before pressing the optical element, such as a headlight lens (or between step (d) and step (e)), a predetermined waiting time is allowed to elapse. In another exemplary configuration, the predetermined waiting time is no greater than 3 seconds (minus the duration of step (d)). In another exemplary configuration, the predetermined waiting time is no less than 1 second (minus the duration of step (d)).
Following the pressing, the optical element (such as a headlight lens) is placed on a transport element 300 as shown in
In addition, before placing the headlight lens 202 on the transport element 300, the transport element 300 is heated such that the temperature of the transport element 300 is approximately +−50 K the temperature of the headlight lens 202 or the edge 206. For example, the heating is carried out in a heating station 44 by means of an induction coil 320, as shown in
In a suitable configuration, it is provided that the support 310 is designed as a rotatable plate. The transport element 300 is thus placed on the support 310 designed as a rotatable plate by hydraulic and automated movement units (e.g. by means of the gripper 340). Centering is then carried out by two centering jaws 341 and 342 of the gripper 340 and specifically such that the transport elements are oriented in a defined manner by means of the marker slot 303, which is or can be detected by means of a position sensor. Once this transport element 300 has reached its linear end position, the support 340 designed as a rotatable plate begins to rotate until a position sensor has detected the marker slot 303.
In a process step 126, an optical element or the headlight lens 202 is moved through a surface-treatment station 45 according to
The transport element 300 together with the headlight lens 202 is then placed on the cooling path 10. In a process step 127, the headlight lens 202 is cooled by means of the cooling path 10.
At the end of the cooling path 10, a removal station 11 is provided, which removes the transport element 300 together with the headlight lens 202 from the cooling path 10. In addition, the removal station 11 separates the transport element 300 and the headlight lens 202 and transfers the transport element 300 to a return transport apparatus 43. From the return transport apparatus 43, the transport element 300 is transferred by means of the transfer station 9 to the heating station 44, in which the transport element 300 is placed on the support 310 designed as a rotatable plate and is heated by means of the induction heater 320.
A process step 128 lastly follows, in which residues of the surface-treatment agent on the lens are washed away in a washing station 46.
It is for example provided that the optical element or lens has a transmission of greater than 90% after washing.
It may be provided that, with reference to the heating of a flat gob, microlens arrays are pressed, which are not used as an array, but instead their individual lenses are used. An array of this kind is for example shown in
The device shown in
By means of the proposed process for manufacturing an optical element or headlight lens, a weathering resistance or hydrolytic resistance or type 1 comparable to borosilicate glass is achieved. In addition, the cost of the manufacturing process in-creases only slightly compared to the manufacturing process of optical elements or headlight lenses with a weathering resistance or hydrolytic resistance corresponding to soda-lime glass. In addition, the optical elements or headlight lenses produced in this way have particularly precise optical properties. This is attributed, for example, to the particular contour fidelity of the described process with simultaneous improvement of the surface quality in the form of a lower surface roughness Ra, e.g. a (surface) roughness of no more than 0.01 μm, for example no more than 0.005 μm. Roughness in the sense of the present disclosure is defined, for example, as Ra, for example according to ISO 4287. The claimed or disclosed process is particularly suitable for extending the range of applications for press-molded lenses, for example with respect to objectives, projection displays, microlens arrays and/or, for example, adaptive vehicle headlights.
As an alternative or variation to the supporting bodies 401 and 501 according to
A cooling block 4501 is provided for cooling the partial lower mold UFT1, which can be cooled by at least one cooling channel 4502 or 4503 and thus cools the partial lower mold UFT1. At least one temperature sensor PTC is provided for controlling the cooling. In one embodiment, several, but at least two, independent cooling channels 4502 and 4503 are provided, which can be set independently of one another or whose flows can be set independently of one another. For example, it is envisaged that the independent adjustability serves to form a desired temperature distribution in the cooling block 4501 or/and thus in the partial lower mold UFT1. In the embodiment shown in
Subsequently, the process step of pressing the preform or blank 4400 into an optical element 4402 corresponding, for example, to the optical element 202 may be performed. In this case, pressing may be performed as described with reference to
As an alternative or variation to the pressing provided with reference to
In a modification of or supplement to the method described with reference to
Following the process described with reference to
Following the heating of the intermediate form 4401 by means of the heating device 4470, the upper mold OF1 and the lower mold UF1 are again moved towards each other, as shown in
The pressing step described with reference to
It may also be provided that the optical element 4402 is further exposed to surface treatment means or sprayed by means of a surface treatment means, as described with reference to
The processes described with reference to
It may be provided that the heating device 872 has a dual function. This is done, for example, when the process is implemented without transporting a partial lower mold UFT1, but when the partial lower mold remains in the press. For example, the heating device 872 serves to heat the partial lower mold UFT1 (and, if necessary, also the partial lower mold UFT2) before receiving a preform 4400. When implementing the process according to
The described method, for example, the method described with reference to modification or partial modification according to
The lens 4402, or the lens shown in
It can be provided that the lens is not rotationally symmetrical but has, for example, a narrow side as shown in
The elements in
Winkler, Markus, Fröhlich, Sven, Diatta, Annegret
Patent | Priority | Assignee | Title |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Mar 03 2022 | DOCTER OPTICS SE | (assignment on the face of the patent) | / | |||
Mar 08 2022 | FRÖHLICH, SVEN | DOCTER OPTICS SE | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 059738 | /0987 | |
Mar 08 2022 | WINKLER, MARKUS | DOCTER OPTICS SE | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 059733 | /0566 | |
Mar 22 2022 | DIATTA, ANNEGRET | DOCTER OPTICS SE | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 059738 | /0950 |
Date | Maintenance Fee Events |
Mar 03 2022 | BIG: Entity status set to Undiscounted (note the period is included in the code). |
Date | Maintenance Schedule |
Mar 19 2027 | 4 years fee payment window open |
Sep 19 2027 | 6 months grace period start (w surcharge) |
Mar 19 2028 | patent expiry (for year 4) |
Mar 19 2030 | 2 years to revive unintentionally abandoned end. (for year 4) |
Mar 19 2031 | 8 years fee payment window open |
Sep 19 2031 | 6 months grace period start (w surcharge) |
Mar 19 2032 | patent expiry (for year 8) |
Mar 19 2034 | 2 years to revive unintentionally abandoned end. (for year 8) |
Mar 19 2035 | 12 years fee payment window open |
Sep 19 2035 | 6 months grace period start (w surcharge) |
Mar 19 2036 | patent expiry (for year 12) |
Mar 19 2038 | 2 years to revive unintentionally abandoned end. (for year 12) |